We have investigated neurotransmitter metabolites and glucose metabolism in incarcerated violent offenders, arsonists and healthy volunteers. We have found that low cerebrospinal fluid (CSF), 5-hydroxyindoleacetic acid (5HIAA) concentrations and hypoglycemia during oral glucose tolerance tests are associated with each other and impulsive violent acts and fire setting. In a follow up study we found that a low blood glucose nadir and low CSF 5HIAA concentration were powerful predictors of recidivism among impulsive violent offenders and fire setters. We are currently collecting lymphocytes for molecular genetic studies from violent offenders, their family members and appropriate controls.